#geotechnical

Geotechnical foundation maths as an API, computed locally and deterministically. The factors endpoint computes the Terzaghi/Vesic bearing-capacity factors Nc, Nq and Nγ from a soil friction angle — Nq = e^(π·tanφ)·tan²(45+φ/2), Nc = (Nq−1)·cotφ and Nγ = 2(Nq+1)·tanφ. The bearing-capacity endpoint computes the ultimate, net and allowable bearing capacity of a strip, square or circular footing from the cohesion, friction angle, soil unit weight, footing width and founding depth, qu = sc·c·Nc + γ·D·Nq + sγ·γ·B·Nγ, breaking it into its cohesion, surcharge and self-weight components and dividing by a factor of safety (default 3) for the allowable value. The settlement endpoint computes the immediate elastic settlement of a footing, s = q·B·(1−ν²)·I / E, from the applied pressure, the footing width, the soil elastic modulus and Poisson's ratio. Cohesion and pressures are in kilopascals, unit weight in kN/m³ and lengths in metres. Everything is computed locally and deterministically, so it is instant and private. Ideal for civil-engineering, geotechnical, foundation-design and construction app developers, footing-sizing and feasibility tools, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is foundation bearing capacity; for lateral earth pressure on walls use an earth-pressure API and for open-channel flow a Manning API.

api.oanor.com/soil-api

Lateral earth-pressure maths (Rankine theory) as an API, computed locally and deterministically for retaining-wall design. The active endpoint computes the active earth pressure that pushes a wall outward when the soil is allowed to yield: the coefficient Ka = (1−sinφ)/(1+sinφ) from the soil friction angle, the pressure at the base of the wall σ = Ka·γ·H, the total thrust per metre run ½·Ka·γ·H², plus the contributions of a surface surcharge and of soil cohesion (which reduces the pressure by 2c√Ka and forms a tension crack of depth 2c/(γ√Ka)). The passive endpoint computes the passive resistance Kp = (1+sinφ)/(1−sinφ) that the soil mobilises when a wall is pushed into it — the resisting pressure and thrust, with cohesion adding 2c√Kp. The atrest endpoint computes the at-rest pressure K0 = 1−sinφ (Jaky) for unyielding walls such as basements and braced excavations. Everything is computed locally and deterministically, so it is instant and private. Ideal for geotechnical and civil-engineering tools, retaining-wall, sheet-pile and basement-wall design, excavation-shoring and foundation apps, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is Rankine lateral earth pressure; for slope geometry use a slope API and for open-channel weir flow use a weir API.

api.oanor.com/earthpressure-api